A thrust bearing is a type of bearing which allows for rotation between parts while supporting an axial load. Fluid film bearings are a type of thrust bearing wherein the bearing's loads are supported on a thin fluid layer or film of liquid or gas which is formed between the bearing surfaces in relative motion. Fluid bearings are often used in many applications covering a wide range of loads and speeds.
Flat land thrust bearings, taper thrust bearings (with or without a land), and tilt pad thrust bearings are three types of fluid film thrust bearings. A flat land thrust bearing utilizes a flat plate or washer, often with radial grooves, to carry the axial load. Taper land thrust bearings utilize plates similar to a flat land thrust bearing but with multiple profiles (taper lands, as one example) machined into the bearing surface. Tilt pad thrust bearings utilize a number of individual segments (or pads), each of which is configured to pivot or tilt to adjust to form a nearly optimal fluid wedge that supports high loads over widely varying speeds in either direction and with a variety of lubricants. In some applications, leveling links are located behind the pivots to accommodate minor misalignment and equalize loads on each of the pads.
Thrust bearings are utilized with a rotating shaft, which includes a thrust collar, runner or block. The distance that a shaft can travel between two thrust bearings is called the end clearance or axial clearance.
Generally, the end clearance is set by the user when assembling the system. The size of the clearance can affect the performance of a system. Specifically, a relatively large clearance may allow for vibrations to occur within the system. For this reason, users need to be very aware of the installation of the bearing and the tolerance of the system.
It is therefore desirable to provide a bearing which is able to account for variation in the end clearance to reduce the need for tight tolerances in a system set up and to reduce clearance to prevent the occurrence of vibrations.